The DSL Forum DSL Forum is an international industry consortium of service providers, equipment and component manufacturers and other interested parties, focussing on developing of broadband DSL. The DSL Forum develops technical specifications and indirectly standards that enable delivery of DSL products and services. More information about the DSL Forum is available from its internet site http://www.dslforum.org.
One of those technical reports is the DSL forum's Technical report TR-069 (e.g. issue 1, amendment 2, dating from December 2007 [also referred to as v1.1 for the purpose of this description]], specifying the CPE WAN Management Protocol (also referred to as CWMP or TR-069). The TR-069 Management Protocol and corresponding network architectures allow communication between a Customer Premises Equipment (CPE) and an automatic configuration server (ACS). It defines a mechanism that encompasses secure auto-configuration of a CPE, and also incorporates other CPE management functions into a common framework.
Apart from the management protocol, DSL Forum also defines in technical report TR-098 the data model to be used for configuration of an Internet Gateway Device (routing gateway). Other DslForum standards define data models for other types of home devices (e.g. TR-104 for Voice over IP CPE, TR-140 for Storage Service Enabled Devices, etc).
Currently, TR-069 only supports management of a CPE by one management server (ACS) at the time. At any time, a CPE is aware of exactly one ACS with which it can connect. [see for instance paragraph 1.5 “Assumptions” of TR-069 (e.g. issue 1, amendment 2, dating from December 2007)].
When the management of the CPE has to be switched to another ACS, a parameter needs to be changed by the initial ACS (e.g. the URL of the ACS) on the CPE, so that the CPE is informed about which management server it has to connect to next.
In the case where different parts of the data model of the CPE are managed by different ACS's, the state of the art method assumes synchronization between the different ACS; the currently managing ACS needs the information on when to change the ACS-URL-parameter on the CPE to pass the management to the next ACS (called switch-over). In another view, the first ACS needs to know when the second ACS has to perform actions on the CPE.
Currently, there is no such standard interface defined between ACS's. Moreover, cases in which more than two ACS's have to provide part of the data model may become difficult to manage.
Furthermore, for the above mentioned system, comprising such a inter-ACS interface, to be commercially useful for multi-ACS CPE management, this interface would have to be standardized, which is not evident.
Furthermore there would be other technical problems associated with such a system, relating to the management of different parts of the object tree by different ACSs. For instance, it would be impossible to support a number of essential TR-069 specific features. Some of those are;                Passive and active notifications (indicating the change of a certain parameter-value in the object tree) are only sent once. Since each ACS wants to manage his own part of the object tree, the active notifications have to end up on the correct ACS. When using the current switch-over mechanism, it is impossible to control to which ACS notifications are to be sent.        Connection requests: in TR-069 a mechanism is defined in which an ACS can request the CPE to set up a session. The CPE can authenticate the ACS, before starting the session. Currently, the CPE only supports authentication of one ACS, and thus it is not possible to authenticate multiple ACS's connection requests.        
Given these and other problems, it is today not possible to apply the current approach, as defined in TR-069, issue 1, amendment 2, of December 2007 and earlier versions, for multi-ACS CPE management.